1. Technical Field
The present invention relates to an authentication system composed of a multiplicity of authentication devices.
2. Description of the Related Art
In the past, in order to confirm whether an unauthorized device is not connected to the system, in an authentication system composed of a multiplicity of authentication devices, each of authentication devices created a session key each other and authenticated other authentication devices each other to confirm whether no unauthorized device is connected.
However, with the prior art there is the risk that if the session key is analyzed and the authentication device is replaced by an unauthorized authentication device that can generate the session key, it will not be possible to detect the replacement by an unauthorized authentication device.
Also, while the authentication device will not start up until authentication by means of a session key is finished, since the authentication data per se is stored in the authentication device, if the authentication device were analyzed, the authentication data could be analyzed as well. As a result, there is a risk that authentication data is forged and an unauthorized authentication is executed.